UBS, which is the world's largest Swiss banking institution, said in a statement that net profits for the first three months of the year were up 19 percent at 1.5 billion Swiss francs (€1.25 billion, $1.5 billion).

"We had an excellent start to 2018, with our results once again showing the power of our diversified business," said CEO Sergio P. Ermotti.

The bank said it was optimistic about the future of the world economy, despite the threat of a US-China trade war and escalating conflict in the Middle East tinderbox.

"We remain confident that global economic growth prospects will continue to provide a supportive backdrop to markets, even though geopolitical tensions and the rise of protectionism remain a threat to investor confidence," the statement said.